This invention relates to the continuous casting of molten metals. It relates particularly to the continuous casting of molten steel between a pair of closely spaced water-cooled rolls whose axes lie horizontally and the rolls rotate in opposite directions.
The continuous casting of molten metal between a pair of closely spaced water-cooled rolls is well-known. Such a process was described and patented as early as 1865 in U.S. Pat. No. 49,053 to Bessemer. Since then there have been a number of other U.S. and foreign patents describing twin roll continuous casting apparatus similar to that of Bessemer but to date, none of these prior twin roll continuous casting machines have been able to produce steel strip of acceptable commercial quality.
In the prior apparatus of Bessemer and the others, the twin rolls were essentially preset with a gap between the rolls corresponding to the strip thickness to be cast. In most of these machines the constrained twin rolls are designed to provide a sufficient force to compress and hot roll the strip as it solidifies to the desired thickness.
We have found that when the twin rolls are constrained there occurs frequent cracking of the solidifying strip as it leaves the rolls, as well as bleeding, tearing and distortion of the strip, making much of the cast product unusable except as scrap.